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<blockquote data-quote="missionpilot" data-source="post: 362925" data-attributes="member: 550420">For the first time for a Momentum Review, I employ the services of my vehicle, a 1990 4 door grand prix for testing. The woofer was tested in both a sealed and ported enclosure, which is mounted down in the floor under the center of the dash. I used a .28 cubic foot (7.9 liter) sealed box, which had a .707 alignment. The ported box was .45 cubic foot (12.7 liters) after displacement, and used a single 2&quot; diameter round port that was 3.2 inches long, giving it a 33hz tuning frequency. Power was provided by the rear bridged channels of a Coustic 320qe amplifier (gained down to 150 watts RMS into 2 ohm mono). Multiple x-over points were tried, and I eventually settled on 90hz with an 18 db /octave slope.This is review off of sound illusions - how big does the total volume of the ported box have to be? does displacement include the volume of the port and the driver or what, the driver displacement is 0.9, and the box after displacement is .45cuft</blockquote>

[QUOTE="missionpilot, post: 362925, member: 550420"] For the first time for a Momentum Review, I employ the services of my vehicle, a 1990 4 door grand prix for testing. The woofer was tested in both a sealed and ported enclosure, which is mounted down in the floor under the center of the dash. I used a .28 cubic foot (7.9 liter) sealed box, which had a .707 alignment. The ported box was .45 cubic foot (12.7 liters) after displacement, and used a single 2" diameter round port that was 3.2 inches long, giving it a 33hz tuning frequency. Power was provided by the rear bridged channels of a Coustic 320qe amplifier (gained down to 150 watts RMS into 2 ohm mono). Multiple x-over points were tried, and I eventually settled on 90hz with an 18 db /octave slope. This is review off of sound illusions - how big does the total volume of the ported box have to be? does displacement include the volume of the port and the driver or what, the driver displacement is 0.9, and the box after displacement is .45cuft [/QUOTE]

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